Valve assemblies for engines and related systems typically utilize rotatable valve members in fluid flow passageways to assist in regulating fluid flow through them. For example, throttle valve members are positioned in the air induction passageways into internal combustion engines. The valve assemblies are controlled either mechanically or electronically and utilize a mechanism which directly operates the valve member.
Known electronic throttle control assemblies utilize a plurality of components which typically are difficult and time consuming to assemble together. Also, the throttle or valve plate is positioned on a throttle body shaft which often experiences undesirable axial, rotary or radial movement which can adversely affect the operation of the valve assembly.
Prior systems, such as described in U.S. Pat. No. 5,746,177, and prior art FIG. 10 of U.S. Pat. No. 5,762,044 used a mechanical fastener to positively secure rotary members to the rotating shaft. These fasteners unnecessarily add cost and weight to the throttle assembly. Other designs, such as shown in FIG. 2 of U.S. Pat. No. 5,429,090, provided a shaft having a substantially rectangular shape at the end thereof. Similar concepts include a D-shape at the end of the shaft. However, these designs were found undesirable in a throttle body application because after several cycles, the material in the member attached to such a shaft became worn and the member became loose to the shaft and would move relative thereto.
U.S. Pat. No. 5,632,245 provides a complicated labyrinth within the end of the shaft into which material is molded to axially and rotationally fix the member. It is expensive and difficult to manufacture such a shaft and it is possible that the material will not flow into the labyrinth machined into the shaft.
It would be desirable to have an electronic valve control system which addressed the above concerns and provides an improved assembly and system, which also reduces costs and improves reliability.